When labels are to be dispensed from a carrier strip at a dispensing edge, also called a detaching edge, the following factors, among others, play an important role:    a) The speed of the dispensing operation. This determines the labeling speed, i.e. how many boxes, cans, bottles, etc. can be labeled per minute.    b) The accuracy of the dispensing operation. What is important here is to place the label accurately at a desired location, for example on a suction device that transfers the label onto an object that is to be labeled, or also to apply the label accurately and without folds at a desired point, directly onto an object to be labeled that is passing by.
Known methods for moving a label strip work in the manner of an open-loop control system, i.e. a label sensor is used that is mounted at a specific location on a labeling device, preferably very close to the location where the labels are dispensed. This location is ascertained empirically by the person setting up the machine. When a label arrives at this sensor, the latter generates a pulse that is then used to shut off the drive system.
Such methods yield entirely acceptable results, but problems occur at higher speeds, principally for the following reasons:
Forces act on the label strip/carrier strip from outside, for example from moving, resilient pendulums on the supply spool and on the spool that takes up the carrier strip. These forces, whose occurrence is governed by chance, can accelerate or decelerate the label strip, which can lead to corresponding labeling errors.
During the motion of the label strip/carrier strip, the latter can expand or contract similarly to a rubber band, particularly at the beginning of a transport motion; this “rubber band effect” can likewise negatively affect labeling accuracy and limits the labeling speed, since such effects increase with increasing speed. This is because higher speeds result in correspondingly higher accelerations, and thus in greater forces on the label strip/carrier strip.